Soils and Foundations最新文献

{"title":"Modifying behavior of calcined waste phosphorus slag on the dispersivity and mechanical properties of dispersive soil","authors":"","doi":"10.1016/j.sandf.2024.101524","DOIUrl":"10.1016/j.sandf.2024.101524","url":null,"abstract":"<div><div>Dispersive soil is a common problem soil in engineering projects, which has the potential risk of causing serious engineering failures. In this paper, calcined waste phosphorus slag (CPS) was chosen to enhance the mechanical properties and reduce soil dispersivity. Dispersive soil samples with 1 % to 10 % CPS content were prepared and cured for 0 to 28 days. The dispersivity identification test was used to assess soil sample dispersivity. The compressive and tensile strength, conductivity, and pH were determined for the soil. Microstructural and mineral composition were analyzed using SEM/EDS, TG/DTG, and XRD analysis. The natural dispersive soil was selected to verify the effect of CPS in improving soil. Experiments show that the CPS inhibits soil dispersivity and converts it into non-dispersive soil. Both compressive and tensile strength increases significantly with the increase in the content of CPS and curing time. The tensile strength of the soil samples cured for 28 days increased by about 76 % and the compressive strength by about 61 % as the mixed content of CPS was increased from 1 % to 10 %. Results show that CPS can improve the strength and modify the dispersivity of soil, its optimal mixing content is 5 %. In addition, using CPS in dispersive soil could also solve the disposal problem of phosphate slag, which is a win-to-win solution.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of suction on time-dependent behavior of intact loess under oedometric conditions: Strain rate dependency and stress relaxation","authors":"","doi":"10.1016/j.sandf.2024.101520","DOIUrl":"10.1016/j.sandf.2024.101520","url":null,"abstract":"<div><div>Many geotechnical failures are associated with degradation of the soil strength over time. The time-dependency behavior of unsaturated loess is often required to evaluate the long-time behavior of geotechnical engineering in loess areas. To investigate such strain rate response and stress relaxation behavior of intact loess, a series of oedometric compression and relaxation tests were conducted under different suctions and strain rates. Water retention behaviors and microstructures were also measured to characterize the tested loess. The more rapid strain rate, leading to larger yield stress at relatively low suctions (0 and 50 kPa) and roughly paralleled one-dimensional normal compression lines (1D-NCL) conformed to the isotache approach. In contrast, the weakening effect of a more rapid strain rate on the clay cementation, resulted in smaller yield stress when the suction was larger than 100 kPa, which was an apparent deviation from the conception of the isotache. The reason might be that the microstructure developed during the long term (slow strain rate) under the relatively larger suction, which may increase the inter-particle bonding and structural strength. The relaxation behavior of unsaturated loess depended on suction and prerelaxation stress, which cannot be well described by the model with a soil constant viscosity <em>I_v</em>. The results of two viscous effects (rate-dependency and relaxation) in loess demonstrated that they could not altogether be explained within the isotache concept.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of foundation damage during earthquakes using acoustic emission monitoring: An experimental study on the shaking table test","authors":"","doi":"10.1016/j.sandf.2024.101473","DOIUrl":"10.1016/j.sandf.2024.101473","url":null,"abstract":"<div><div>Assessing structural foundation damage following an earthquake is critical for safety evaluation. However, assessing the damage to pile foundations with traditional visual inspections and non-destructive testing methods is challenging. This study evaluated the use of acoustic emission (AE) monitoring for damage detection and location in foundation structures during earthquake simulations by conducting shaking table experiments. Scaled models of foundation structures with and without surrounding soil were used in the experiments, and the performance of the AE monitoring system was evaluated by comparing the AE parameters via visual inspection. The experimental results showed that the AE monitoring system could effectively predict the initiation of cracks in foundation structures that experienced an earthquake. In addition, an appropriate filtering criterion for the shaking table experiments was established based on the AE characteristics of the foundation structures during the earthquake simulation, thereby improving the performance of the AE monitoring system for damage location. Consequently, this study contributed to a better understanding of the applicability of AE monitoring systems to foundation structures during earthquakes.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A machine learning-based method for predicting the shear behaviors of rock joints","authors":"","doi":"10.1016/j.sandf.2024.101517","DOIUrl":"10.1016/j.sandf.2024.101517","url":null,"abstract":"<div><div>In this study, machine learning prediction models (MLPMs), including artificial neural network (ANN), support vector regression (SVR), K-nearest neighbors (KNN), and random forest (RF) algorithms, were developed to predict the peak shear stress values and shear stress-displacement curves of rock joints. The database used contained 693 records of peak shear stress and 162 original shear stress-displacement curves derived from direct shear tests. The results demonstrated that the MLPMs provided reliable predictions for shear stress, with the mean squared errors (MSEs) between their predicted and measured shear stress varying from 0.003 to 0.069 and the coefficients of determination (R² values) varying from 0.964 to 0.998. The feature importance values indicate that the joint surface roughness coefficient (JRC) is the most important influential factor in determining the peak shear stress, followed by the joint wall compressive strength (JCS), basic friction angle (<span><math><msub><mi>φ</mi><mi>b</mi></msub></math></span>), and shear surface area (<em>A</em>_s). Similarly, for the shear stress-displacement curve, the JRC is the dominant factor, followed by <em>A</em>_s, <span><math><msub><mi>φ</mi><mi>b</mi></msub></math></span>, and JCS. Additional direct shear tests were conducted for model validation. The validation shows that the MLPM predictions demonstrate improved consistency with the experimental results in relation to both the peak shear stress and peak shear displacement.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on mechanical behavior of silty-fine sand reinforced by a new type of permeable polymer material under dry-wet cycles","authors":"","doi":"10.1016/j.sandf.2024.101519","DOIUrl":"10.1016/j.sandf.2024.101519","url":null,"abstract":"<div><div>Silty-fine sand in the Yellow River floodplain is prone to geological hazards such as collapse, subsidence, gushing water, and sand routing triggered by groundwater seepage. As a new type of grouting material, permeable polymer is effective for solving silty-fine sand geologic hazards. With the rise and fall of the water table, capillary water, and transpiration, the reinforced silty-fine sand will be subjected to dry-wet cycles. Investigating the strength loss mechanism of specimens reinforced with permeable polymer during dry-wet cycles is essential for mitigating silty-fine sand geological hazards. The strength characteristics of permeable polymer grout-reinforced silty-fine sand specimens under dry-wet cycles and its extreme case (long-time immersion) were analyzed from macro and micro perspectives employing unconfined compressive strength (UCS) test and scanning electron microscope (SEM). The functional calculation model between the specimens and the initial grouting conditions under dry-wet cycles was constructed, and the main influencing factors of the UCS loss of the specimens were obtained. After permeable polymer grouting, the porosity of silty-fine sand is reduced effectively and the porous structure is changed. The grouted specimens maintain structural integrity and demonstrate excellent water stability even after dry-wet cycles.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospective method to estimate shear stress in the ground using two earth pressure cells","authors":"","doi":"10.1016/j.sandf.2024.101504","DOIUrl":"10.1016/j.sandf.2024.101504","url":null,"abstract":"<div><div>Many sophisticated numerical methods have been developed to evaluate soil responses. However, the lack of referential stress–strain behavior under complicated in-situ ground conditions makes it difficult to validate the obtained responses sufficiently. For example, under a long embankment, with imposing plane strain conditions in depth, allowing for both horizontal displacement toward the slope toe and settlement, the stress components change as a result of the interaction between one soil part and adjacent soil parts. Since those stress conditions themselves are unknown, no laboratory experimental data can be provided to validate a constitutive model. Therefore, the author considered that studying the stress conditions in the ground would play an important role in confirming the calculated results obtained by a numerical method. Soil stress cells have sometimes been utilized to measure the earth pressure in an experimental model, but such measurements have often proven to be unreliable or unrealistic. However, the preciseness of earth pressure meters has recently been examined and improved. Recently, centrifuge tests were conducted to estimate the shear stress in a horizontally layered model ground during shaking. By using a pair of earth pressure meters and the concept of Mohr’s stress circle, it was possible to estimate the shear stress at any point in the ground. The shear stress estimated by this method was seen to agree well with the results obtained by a calculation based on the force balances of the supposed soil blocks from the ground surface. As a result, it was confirmed that the proposed method is a promising way to estimate the shear stress in the ground and is worthy of further investigation.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between void characteristics and re-liquefaction resistance: An image analysis study","authors":"","doi":"10.1016/j.sandf.2024.101506","DOIUrl":"10.1016/j.sandf.2024.101506","url":null,"abstract":"<div><div>To scrutinize the impact of void characteristics on re-liquefaction resistance, a series of constant-volume cyclic bi-axial tests was conducted on an assembly of plastic rods. The first and second liquefaction stages involved the application of isotropic compression at 100 kPa followed by constant-volume cyclic loading with the deviator stress set at 30 or 60 kPa. This study introduced an innovative image analysis method to quantify four void characteristics: anisotropy index (<span><math><mrow><msub><mi>I</mi><mi>e</mi></msub></mrow></math></span>) and average void element size (<span><math><mrow><msub><mi>A</mi><mi>e</mi></msub></mrow></math></span>) for the element-based analysis, and local anisotropy index (<span><math><mrow><msub><mi>I</mi><mrow><mi>e</mi><mo>,</mo><mi>i</mi><mi>j</mi></mrow></msub></mrow></math></span>) and local void ratio (<span><math><mrow><msub><mi>e</mi><mrow><mi>ij</mi></mrow></msub></mrow></math></span>) for the grid-based analysis. The newly developed anisotropy index was seen to facilitate the assessment of the primary alignment and degree of anisotropy in void elements. The results confirmed that an increase in re-liquefaction resistance is evident in specimens with lower average <span><math><mrow><msub><mi>e</mi><mrow><mi>ij</mi></mrow></msub></mrow></math></span>, coefficient of variation (CV) of <span><math><mrow><msub><mi>e</mi><mrow><mi>ij</mi></mrow></msub></mrow></math></span>, and <span><math><mrow><msub><mi>I</mi><mi>e</mi></msub></mrow></math></span>, indicating denser, more homogeneous, and isotropic conditions. Nevertheless, specimens with a greater degree of anisotropy were found to be more susceptible to re-liquefaction. The development of strain in the early stages of cyclic loading was found to be predominantly influenced by the anisotropy index, underscoring the imperative need for an enhanced method that can predict liquefaction resistance, as well as re-liquefaction resistance, and incorporates the anisotropy index.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080624000842/pdfft?md5=a9d3d5e42f6f66a603f7a17f8a1ac1c8&pid=1-s2.0-S0038080624000842-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudo-dynamic bearing capacity of strip foundations on rock masses considering the Rayleigh surface waves","authors":"","doi":"10.1016/j.sandf.2024.101508","DOIUrl":"10.1016/j.sandf.2024.101508","url":null,"abstract":"<div><p>Evaluation of seismic bearing capacity is to be vital for design of strip foundations in earthquake areas. Combining the upper bound theorem of limit analysis, the discrete technique is successfully extended in this study to investigate the seismic ultimate bearing capacity of shallow strip foundations on rock masses considering the Rayleigh waves, in which the nonlinear HB failure criterion is used to describe the constitutive relation of rock masses. The failure model of foundation soil is generated using the discretization method, a “point by point” technique. The variations of shear modulus <em>G</em> of rock masses and seismic acceleration varying with the depth are taken into consideration. The generalized tangential technique is employed to avoid the difficulty resulting from the nonlinear HB failure criterion. A linear corresponding to the Mohr–Coulomb failure criterion, tangent to the nonlinear Hoek–Brown failure criterion, is used to derive the objective function that is to be minimized. By comparing with the existing results, the present approach is verified. The widely parametric studies are made to investigate the effect of different parameters, e.g. shear modulus <em>G</em>, <em>m_i</em>, <em>GSI</em>, <span><math><mrow><msub><mi>σ</mi><mrow><mi>ci</mi></mrow></msub></mrow></math></span>, <em>γ</em>, <em>D</em>, <em>V_R</em>, on the seismic bearing capacity of strip foundations. The present method provides a reference for strip foundations designed in earthquake areas.</p></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080624000866/pdfft?md5=9ec8a164bcd978aecd4ceab01c6b2471&pid=1-s2.0-S0038080624000866-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of silt uniformity on the liquefaction resistance of sand–silt mixtures","authors":"","doi":"10.1016/j.sandf.2024.101507","DOIUrl":"10.1016/j.sandf.2024.101507","url":null,"abstract":"<div><p>Literature review revealed that effects of particle segregation and silt uniformity on the liquefaction resistance of sand–silt mixtures are not well understood. Therefore, cyclic direct simple shear tests were conducted to investigate effects of silt uniformity and stratified structures on the liquefaction resistance of sand–silt mixtures with 0%–40% fines content (<em>FC</em>). For all uniform sand–silt mixtures, as <em>FC</em> increased up to 20%, liquefaction resistance decreased, while it increased as <em>FC</em> increased from 20% to 40%. The liquefaction resistance of the samples with uniform silt only in the top and bottom layers was slightly higher than that of a uniform sample (<em>USM</em>), while the cyclic strength of the samples with silt concentrated in the middle layer was greater (up to 23%) than that of other nonuniform samples. <em>USM</em> exhibited the least liquefaction resistance. In addition, the number of silt layers (<em>NoSLs</em>) substantially affected the liquefaction resistance of stratified structures: as <em>NoSLs</em> increased from 1 to 3 layers, the cyclic resistance ratio was reduced by 20%, 10%, and 7% for <em>FC</em> values of 20%, 30%, and 40%, respectively. The liquefaction resistance of the stratified samples was greater than that of <em>USM</em>. To quantify the effect of silt uniformity and <em>NoSLs</em>, the nonuniformity index (<em>NUI</em>) was introduced herein; the calculated <em>NUI</em> values showed that the increase in liquefaction resistance was well correlated with the increase in the <em>NUI</em>.</p></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080624000854/pdfft?md5=7a612a407650476e3e677a2129ea3ebe&pid=1-s2.0-S0038080624000854-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastoplastic finite element simulation of domino fault formation associated with tilting of highly structured ground","authors":"","doi":"10.1016/j.sandf.2024.101475","DOIUrl":"10.1016/j.sandf.2024.101475","url":null,"abstract":"<div><p>Ground deformation on the Earth’s surface layer is strongly affected by the nonlinearity of geomaterials. However, the formation process of such deformation has yet to be described in a unified manner based on mechanics. The present study focuses on the normal faults in a submarine ground with highly developed soil skeleton structures and attempts to reproduce the process of normal fault formation associated with the tilting of a horizontally deposited submarine ground using an elastoplastic finite element simulation. The simulation was conducted using the soil–water coupled finite deformation analysis code <strong><em>GEOASIA</em></strong>, which incorporates an elastoplastic constitutive equation of the soil skeleton based on the modified Cam-clay model and the soil skeleton structure concept. The key findings are as follows:</p><p>1) Normal faults are formed from the ground surface to depth as shear bands, where shear strain is localized while exhibiting softening behavior with plastic volume compression.</p><p>2) Multiple normal faults are almost equally spaced and parallel to each other, with the inter-fault blocks rotating backward. The morphology of normal faults formed by the tilting of the ground shows domino-style characteristics.</p><p>3) The degree of the soil skeleton structure influences the formation of normal faults.</p><p>This study demonstrates that elastoplastic geomechanics can explain the formation process of ground deformation, which has usually been interpreted from the perspectives of geomorphology and geology.</p></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080624000532/pdfft?md5=74671d3f89186100e822b4a6c7c67d6f&pid=1-s2.0-S0038080624000532-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}